<p>
  <mat-checkbox [formControl]="disableSelect">Disable select</mat-checkbox>
</p>

<h4>mat-select</h4>
<mat-form-field>
  <mat-label>Choose an option</mat-label>
  <mat-select [disabled]="disableSelect.value">
    <mat-option value="option1">Option 1</mat-option>
    <mat-option value="option2" disabled>Option 2 (disabled)</mat-option>
    <mat-option value="option3">Option 3</mat-option>
  </mat-select>
</mat-form-field>

<h4>native html select</h4>
<mat-form-field>
  <mat-label>Choose an option</mat-label>
  <select matNativeControl [disabled]="disableSelect.value">
    <option value="" selected></option>
    <option value="volvo">Volvo</option>
    <option value="saab" disabled>Saab</option>
    <option value="mercedes">Mercedes</option>
    <option value="audi">Audi</option>
  </select>
</mat-form-field>

